(a) The registration by the board on or before December 31, 1973, of a structure located in whole or in part on coastal public land on August 27, 1973, and claimed by the person submitting it for registration as an incident of the ownership of littoral property shall not be construed as evidence of the acquiescence of the state in the claim by the owner.
(b) Failure of the owner to register the structure estops the owner from making any further claim of right against the state in the structure and renders the structure a nuisance per se subject to abatement by the state at the expense of the littoral owner.